The goal of this project is an understanding of collagen structure from the molecular to the fibril level. Emphasis is presently on two aspects of the general problem. 1) Computer analysis of the primary structure of collagen for distributional or interactional patterns related to molecular packing. 2) Computer enhancement and analysis of electron micrographs to reveal detail not obvious to the eye. BIBLIOGRAPHIC REFERENCES: Trus, B.L. and Piez, K.A.: Molecular Packing of Collagen: Three-Dimensional Analysis of Electrostatic Interactions. J. Mol. Biol. 108, 705-732, 1976. Piez, K.A. and Trus, B.L.: Microfibrillar Structure and Packing of Collagen: Hydrophobic Interactions. J. Mol. Biol. 110, 701-704, 1977.